This is the special report. From ABC news now. And good afternoon everyone I'm Dan -- in New York bring -- response to reports. Bear -- you see shots in the east room of the White House the president about to make an announcement for his new chief of staff. Let's go and listen in as the president will make this announcement. Good afternoon everybody and welcome. To the announcement of one of the worst kept secrets in Washington. Just president I rely on an extraordinary team of men and women. Here at the White House ever signaled that and I rely on my chief of staff. To keep -- -- in our entire government. Make -- the world moving in the same direction. -- ensure that my priorities are being carried out in our policies are consistent with. The commitments that I've made of the American people and that we're delivering progress. To the American people. As I said earlier this month I could not be more grateful to Jack Lew. For his amazing service. First is our OMB director than at the State Department. And ultimately. As my chief of staff. Is he prepares for his confirmation hearings. And the challenge of leading our Treasury Department. I'm pleased to announce my next chief of staff. And a great friend to me. And everybody who works here at the White House mr. -- I have been counting on -- for nearly a decade. Since I first came to Washington. When he helped set up my senate office. Along with -- Pete Rouse. You know he. Was able to show me where the restrooms word. -- you passed a bill. I should point out that even then Dennis had greater. I've been trying to catch up -- But at that time. I relied on his intellect and his good judgment every and that has continue to -- He's been one of my closest most trusted advisors. On my presidential campaign on my transition team he has been an indispensable member of my national security team as well. Dennis has played a key role in every major national security decision in my presence. From ending the war in Iraq and winding down war and Afghanistan. From our response to natural disasters around the world like -- and the tsunami in Japan. To the repeal of Don't Ask Don't Tell. Countless crises in between. -- and -- And that includes many nights. I've actually begin to think that Dennis likes pulling all -- That the truth is nobody. Out works Denis McDonough. And -- part of the reason you saw such warmth and clauses that in addition to being an incredible tale and such a hard worker that was also pretty -- -- To so many of his friends of the Myers he's still just the dude from Stillwater Minnesota. And given his humility. I don't think people always. Appreciate the breadth of his experience and range of -- tell us. And is precisely because of that in lacks that experience. His dedication. His determination that I wanted Dennis in this job. As veteran of Capitol Hill where he was mentor by the likes Lee Hamilton and Tom Daschle. -- understands the importance. Reaching across the -- to deliver results for the American people whether it's on jobs in the economy health care education. Reducing the deficit or addressing climate change. Dennis is respected by leaders across our government. And it all up and I think he spent most of the past four years leading interagency meetings. Curing people out. Listening to them forging consensus and then making sure that our policies are. And that everybody's held accountable and he always hold himself accountable first and foremost. And it's no easy task but through -- all Dennis -- -- -- class. And integrity. And fought homeless for other people's point of -- he's the consummate public servant he plays straight. And that's the kind of teamwork that I want in the White House. Time and again relied on -- to help in our outreach the American people as well including immigrant and minority communities and fake news. And this is a man of deep -- And he understands that in the end our policies and programs are measured in this concrete differences that they make in the lives. Of our fellow human beings and in the values that we advance as Americans. Dennis insists on -- for himself the real -- -- the decisions that we make so away from the cameras. Without a lot of fanfare. He's visited our troops in Iraq and Afghanistan repeatedly. -- their concerns finding out what they need in the making sure to follow. He travels to Walter Reed again without -- to spend time -- wounded warriors getting to know them and what we as a nation can do take care of them and their fans. And then he comes back here on the White House and he gets it done and that's the kind of focus. But also would -- heart. That I want. In -- sports. That don't get me wrong Dennis can be -- It probably comes from one of eleven children you've got to be tough. To this it's sisters are here today by the way Marion and I and I know they could that is beating me. More proud proud mother the brother. Maybe it comes from his college football days as defensive back. Under the legendary John go -- I always -- -- that. You know he made up four. Modest talents would extraordinary dedication. And a -- threshold for pain. This does remind -- -- perhaps one topic on which -- and I will never agree and that is vikings vs barriers. There's another reason we all loved us so much and that's -- decency his respect for those around. Ask any of the staff who were here today. And they'll tell you that despite. The unbelievable pressures. Of service at the -- Dennis is still the first to think about a colleague or to write -- handwritten note saying thank you to ask about your family. That's the spirit that I want and that's what it's. And this of course is reflected in his incredible -- -- -- Party. Andy Williams Teddy. I know that -- -- work a lot. During the week and on weekends. And I guarantee -- -- much rather be -- -- -- with me. The next job is gonna have is going to be demanding to but. The one reason he does this is because he wants to make sure that the world's a better place for all of you. Dad will probably have to stop riding his bike to work. As chief of staff I don't think that's allowed. But he is. He does what he does because he cares Las -- -- wants to make sure it. The next generation. America that we -- want. So. I'm grateful to them in retirement and family report problems. Dennis you're not just -- Michael's friends are also. My closest advisors. Like your -- here I cannot imagine -- -- about your thank you for signing up for this. Very very difficult job -- will testify. I know you always give it to me straight. As only a friend -- Telling me not only what I want to hear but more importantly what I need to hear make responsible decisions on behalf of the American people. So. For me for Michelle. For all your friends colleagues were here today thank you -- missed assignment. -- Does have one of thing that add. That we made a number of personnel announcements today there's going to be an incredible team. That. Dennis will help lead. But I thought I'd take the occasion to just embarrass somebody. Some of you. May know that today's David -- last -- in the White House. I had -- this in the end -- remarks. Because I knew he would want me to bring it up so that we had some secrets squirrel stuff going on here. Avoid him thinking that we're gonna talk program. But. As many of you know. David has been. With -- me from the very start this. This enterprise. Running for president. I can't tell you how lucky I have been to have him. Can't manage our campaign. Back in 2008. Then join the White House during. These very challenging last two years. He's built. A well deserved reputation as being there. They numbers genius and -- They're pretty. Tough combatant. When it comes to politics but what people don't always realize because he doesn't like to -- -- The reason he does this stuff is because he cares deeply about people and he cares about justice he cares about. Making sure that are but he gets shot life. Those values. Have motivated him. To do incredible things and that -- not for him. We would not have been as effective -- White House. I probably won't be here so I thought it was worthwhile. For us to Syria. Even if he does Morris say it thank you David -- -- -- -- Make any announcement there -- Denis McDonough will take over as White House chief of staff taking over for Jack Lew Jack Lew will be replacing Tim Geithner over at the Treasury Department. President longtime trusted advisor -- -- also a national security expert he's very popular. Inside the Obama inner circle essentially since his senate days. Of course has the president's second term gets underway more of these announcements and appointments. Coming to light in the next couple of days this has been an ABC news special report a full report on abcnews.com.

This transcript has been automatically generated and may not be 100% accurate.

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